During important periods of growth and development, animals are highly sensitive to their nutritional environment and can modify their metabolism, causing changes that persist throughout life. Poor nutrition early in life can lead to maladaptations that later increase the risk of metabolic disorders such as type 2 diabetes and heart disease. Recent studies indicate that early nutritional exposures may also directly affect longevity and cellular processes associated with aging. However, due to the costly nature of longitudinal animal studies, it is difficult to compare the effects of diverse dietary exposures an age groups. In addition, the cellular mechanisms underlying the effects of early diet on metabolism and aging are largely unexplored. This application establishes a novel platform using the fruit fly, Drosophila melanogaster, to investigate the role of early nutrition on lifespa and overall health. The proposed aims will dissect the fundamental epigenetic mechanisms and physiological changes that underlie the effects of poor nutrition during critical periods of development on metabolic aging. These studies will provide new strategies and genetic targets for pharmacological interventions that reverse the effects of poor early diet and potentially improve human healthspan.